1. Field of the Invention
The present invention relates to a fluid transferring apparatus which transfers fluid with use of reciprocal motion of wings in a transverse direction in a flow passage, in a manner like the flapping movement of bees.
2. Description of the Prior Art
A cross flow fan has conventionally been used, for example, in many air conditioners as a fluid transferring apparatus to realize a two-dimensional flow. In comparison with a propeller fan, a sirocco fan, etc. which achieves a three-dimensional flow, however, the cross flow fan is disadvantageous in its low efficiency and restrictions on design. That is, although it is effective to enlarge the diameter of a fan in order to reduce noises, a large space is necessitated therefor and a shape, of a scroll part, a stabilizer or the like greatly influences the efficiency of the cross flow fan.
Therefore, a fluid transferring apparatus of a perfectly new type has been desired and a proposal for utilization of a so-called Weis-Fogh mechanism, e.g., as disclosed in Japanese Patent Laid-open Publication 64-107000 has been made to realize a two-dimensional flow with high efficiency and reduced noises.
In the meantime, the Weis-Fogh mechanism referred to above utilizes a new propelling method discovered when the flapping of bees is observed. As indicated in the above-mentioned prior art as well, according to the Weis-Fogh mechanism, two wings are provided within a flow passage and moved in parallel to each other in a manner to alternately be brought close and separated in a direction orthogonal to the flow passage, while an attack angle of each wing is changed at both ends of its stroke.
However, a driving mechanism would be considerably complicate and hard to operate at high speeds if the wings were driven by mechanical means strictly in compliance with the Weis-Fogh mechanism. Therefore, no suitable example of an actual application of the Weis-Fogh mechanism has been embodied so far, and the above prior art also does not clearly disclose a concrete driving mechanism, thus calling for a technique enabling realization of the Weis-Fogh mechanism in a simple manner.